The purpose of this study was to determine whether normal human epidermis could produce
leukotriene B 4 (LTB 4) from leukotriene A 4 (LTA 4) ex vivo; and to localize this LTA 4-
hydrolase activity. Epidermis obtained by suction blister technique incubated with human
polymorphonuclear cells, resulted in a 54% increase in LTB 4 formation when compared to
polymorphonuclear cells incubated alone. Furthermore, human epidermis transformed
exogenous LTA 4 into LTB 4, and this reaction obeyed Michaelis-Menten kinetics with an …